The electrical characteristics of x-ray and γ -ray detectors with Schottky diodes on the basis of CdTe crystals of n-type conductivity with a resistivity of 10 2 -10 3 cm (300 K) are investigated. The necessary parameters of the diode structures are determined to interpret the detection characteristics of the detectors. The dependences of the charge-collection efficiency in the detectors on the carrier lifetime and concentration of uncompensated donors are obtained and the conditions for the total collection of charges generated by the photon absorption are established. Taking into account drift and diffusion photocurrent components, the spectral distribution of the quantum detection efficiency is calculated. The comparative analysis of the detection efficiency of Schottky diodes based on low-resistivity p-CdTe and n-CdTe shows the advantages of the latter, especially in a low x-ray energy region.

A theoretical and experimental study is made of the piezoresistance of p-and n-type CdSb. The stress applied along the three crystal axes produces a change in the resistivity of opposite sign. The proposed theory of noneyuivalent valley A , A , and 2, which follows from the low symmetry of the crystal, explains the observed effects in n-type CdSb, while a theory involving three nonequivalent shifted valence-maxima in r is in good agreement with the experimental results for p-type CdSb.Der Piezowiderstand von p-und n-CdSb murde theoretisch und experimentell untersucht. Die entlang der drei Kristallaehsen angelegten mechanischen Spannungen erzeugen Widerstandsanderungen mit unterschiedlichem Vorzeichen. Die Ungleichwertigkeit der Taler A, A und Z, die sich aus der niedrigen Symmetrie des Kristalls ergibt, erklart die beobachteten Effekte in n-CdSb, wiihrend eine Theorie von drei gegeneinander verschobenen nicht-Pquivalenten Valenzbandmaxima in r sich in guter Ubereinstimmung mit den experimentellen Ergebnissen in p-CdSb befindet. 208

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Schottky barrier photodiodes obtained by vacuum evaporation of the semi‐transparent film over the surface of single crystalline Hg3In2Te6 substrates pre‐treated by Ar ion bombardment. The responsivity maximum of the photodiodes is at the wavelength of 1.55 μm, corresponding to the transmission window in silica glass fiber with the minimal optical losses. The dark current in the diodes is determined by generation‐recombination processes in the space‐charge region and quantitatively governed by the Sah–Noyce–Shockley theory. A comparison of the photoelectric parameters of Hg3In2Te6 and Ge photodiodes is reported. The speed of the photodiode response is in the range 10–8 s to 10–7 s. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)